A necessary condition for the application of EU antitrust rules. Articles 101 and 102 of the EC Treaty are only applicable if there may be a direct or indirect, actual or potential influence on the flow or pattern of trade between at least two Member States of the EU. An effect on trade exists in particular where national markets are partitioned or the structure of competition within the common market is affected. Anti-competitive agreement or conduct that have no effect on trade, therefore, fall outside the scope of the EU competition rules and may only be dealt with by national legislation.

The merger regulation, by contrast, applies where a concentration has a Community dimension defined in terms of turnover thresholds.

Source: Glossary of terms used in EU competition policy, Antitrust and control of concentrations, European Commission, 2002